JPS645332Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a thermal overcurrent relay used in a push-button operated electromagnetic switch.

Conventional push-button-operated electromagnetic switches consist of an electromagnetic contactor and a thermal overcurrent relay, and are equipped with contact mechanisms for starting and stopping on the surface of the main body. For this reason, the structure is complicated, and the components of the command contact mechanism have different dimensions and shapes for each model, making it difficult for manufacturers to manage the large number of parts. In addition, the stop command contact mechanism attached to the thermal overcurrent relay is located close to the current adjustment dial due to the circuit configuration, so care must be taken to avoid contact with current-carrying parts when operating the dial during operation. It was hot.

This invention was made in order to solve this problem, and by devising the structure of the conventional reset push button to also have a stop command function, it is possible to reduce the cost of push button operated electromagnetic switches. This is aimed at improving down and safety performance.

That is, this invention provides a thermal overcurrent relay equipped with a reset push button for a movable contact that is operated via a transmission lever by bending an operating bimetal.
A fixed contact is provided on the support plate electrically connected to the movable contact, and a terminal is provided on the container frame with a normally closed movable contact that contacts the fixed contact, and the reset push button is provided with the normally closed movable contact. By providing a sliding portion that opens and covers the contact, the reset push button has the function of a stop button.

Embodiments of this invention will be described below based on the drawings.

Fig. 1 is a partially cutaway plan view of an embodiment of this invention, and Fig. 2 is a vertical sectional side view.
This is a container frame made of an insulating material such as synthetic resin and provided with a. Reference numeral 2 denotes a movable contact support plate presser made of a conductive material and formed in a U-shape.
A, the other leg is fixed to the inner wall of the container frame, and a fixed contact 17 is provided at the connecting portion. Reference numeral 3 denotes a movable contact support plate made of a conductive material and fixed to the movable contact support plate presser, and support arms 3a and 3b are provided at the legs of the movable contact support plate 3. 4 is a normally closed fixed contact;
It is fixed at a. Reference numeral 5 denotes a movable contact made of a conductive spring material, and a movable contact 6 is provided at one end, and a center leg 5b formed by a vertical groove and a side leg 5a, 5a are provided at the other end. 5b
to the support arm 3b, and both legs 5a, 5a to the support arm 3b.
It is locked to a and 3a. Reference numeral 7 denotes a current adjustment dial rotatably provided on the container frame 1, and an eccentric cam 7a is provided at the tip thereof. Reference numeral 8 is a temperature correcting bimetal whose one end is fixed to the movable contact support plate 3, and whose end is brought into contact with the eccentric cam 7a. 9 is a pressure spring mounted between the temperature correction bimetal 8 and the container frame 1, and 10 is a reset/stop push button supported on the container frame 1 so as to be able to move up and down, as shown in Fig. 3. A recess 10d in which a return spring 11 is housed between the container frame and a reset/stop push button 10.
When pressed down, the movable contact 5 is tilted,
A protruding piece 10b that closes a circuit, a notched groove 10c through which the temperature correction bimetal 8 is inserted, and an inclined surface 10a that contacts the head of a normally closed movable contact 18 described later and is inclined upward are provided. 12 is a bimetal for operation, one end of which is fixed, and the other end of which is engaged with the transmission lever 13. 14 is a U-shaped member pivotally supported on a pin 15, having one leg engaged with the transmission lever 13 and the other leg having a protrusion 14a that presses the center leg 5b of the movable contact 5 to operate the contact 5. This is the drive lever.

16 is an adjustment screw, 17 is a fixed contact fixed to the movable contact support plate presser 2, and 18 is a normally closed movable contact made of an elastic plate, which has a movable contact 19 in the center as shown in FIG. One end is fixed to a normally closed movable contact plate 20, and the other end is a reset/stop push button 1.
The fixed contact 17 and the movable contact 19 are normally held in pressure contact. 21 is a cover mounting screw.

FIG. 5 shows a circuit diagram in use, where M is an electric motor, 23 is a starting push button 26 having a thermal overcurrent relay 24, an electromagnetic contactor 25, and a self-holding contact 27 according to this invention. This is a push button operated electromagnetic switch.

Now, when the starting push button 26 is pressed, the electromagnetic contactor 25 operates the normally closed fixed contact 4 of the thermal overcurrent relay 24 - the movable contact support plate presser 2 - the normally closed movable contact plate 20
Even if the starting push button 26 is released by the self-holding contact 27 of the electromagnetic contactor 25, the electromagnetic contactor is self-maintained and the electric motor M starts. Next, when the reset/stop push button 10 of the thermal overcurrent relay 24 is pressed, the normally closed movable contact 18 moves to the left, and the contact between the movable contact support plate holder 2 and the normally closed movable contact plate 20 17 and 19 are opened, the electromagnetic contactor 25 is deenergized, and the electric motor M is stopped.

As described above, if the thermal overcurrent relay according to this invention is used, there is no need to provide a separate stop command push button as in the past when constructing a push button operated electromagnetic switch 23. This simplifies assembly and wiring work, and ensures safety in operating the current adjustment dial during operation.

Although FIG. 1 shows an embodiment with a 1b contact mechanism, it is also possible to manufacture a 1c contact mechanism by changing some parts. Although FIG. 1 shows an embodiment of the manual return type, the reset button can be changed to the one shown in FIG.
An automatic return type can also be manufactured by changing the structure to protrude more than shown in the figure. Also the first
Although the figure shows an example of a structure with a two-pole heater, it is clear that it does not necessarily have to be a two-pole heater and can also be implemented with a three-pole heater.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view of an embodiment of this invention, Fig. 2 is a vertical side view thereof, Fig. 3 is a perspective view of the reset/stop push button, and Fig. 4 is a normally closed movable contact. FIG. 5 is an electric circuit diagram of a push-button operated electromagnetic switch, and FIG. 6 is a partially cutaway plan view of a different embodiment. 1... Instrument frame, 2... Movable contact support plate holder, 4
... Normally closed fixed contact, 5 ... Movable contact, 6 ...
Movable contact, 10...Push button for reset and stop, 10
a... Inclined surface, 12... Bimetal for operation, 13
...transmission lever, 17... fixed contact, 18... normally closed movable contact, 19... movable contact, 20... normally closed movable contact plate, 23... push button operated electromagnetic switch, 24... heat Dynamic overcurrent relay, 25...Magnetic contactor.

Claims (1)

[Scope of utility model registration request] A thermal overcurrent relay equipped with a reset push button for a movable contact that is operated via a transmission lever by bending an operating bimetal, and a fixed contact is provided on a support plate electrically connected to the movable contact; The thermodynamic type override is characterized in that the device frame is provided with a terminal having a normally closed movable contact that contacts the fixed contact, and the reset push button is provided with a sliding portion that opens and covers the normally closed movable contact. Current relay.